The present invention relates to a disk array apparatus (also called “storage apparatus”), which has a storage unit such as a hard disk drive (HDD) and a storage control unit (hereinafter referred to as “DKC”) for controlling data storage with respect to the storage unit and is controllable in RAID format. Especially, the present invention relates to a technology for mounting the DKC with a board (circuit board) and its package (hereinafter abbreviated as “PK”).
In a conventional disk array apparatus, the DKC is configured by interconnecting the boards on which multiple processing units corresponding to facilities are mounted, for example. The facilities are an I/F (interface) for an external device such as a host computer (hereinafter also called “host”) communicatively connected to the DKC, an I/F for a HDD (hereinafter also called “drive”), a memory such as a cache memory (hereinafter referred to as “CM”) for caching data, and a switch for transferring data between respective units. The I/F for the external device such as the host (referred to as “channel I/F” or “host I/F”) has various types such as a fiber channel (hereinafter referred to as “FC”). The I/F for the HDD (referred to as “disk I/F” or “drive I/F”) also has various types such as a SCSI. A processing unit corresponding to the channel I/F is referred to as a channel control unit (CHA). A processing unit corresponding to the disk I/F is referred to as a disk control unit (DKA). In the board corresponding to each facility and/or the PK of the board, the board for each I/F includes a plurality of same kind of I/F ports, wherein a communication processing of the corresponding I/F and a data transfer processing by a DMA (direct memory cell) are performed.
A portion, which mainly includes the board and integrally formed together with an electrical/mechanical structure for mounting/connecting the board to a chassis of the disk array apparatus, will be referred to as a PK in this specification. Each of the PKs constituting the DKC is referred to as a control PK. The PK may have a configuration and a structure in which the PK is inserted and drawn to/from a slot of a box in the chassis.
As one function of the disk array apparatus, it is demanded that the data transfer between different kinds of I/Fs can be performed in one DKC (also called “virtualization”). The different kinds of I/Fs are conventionally provided as the different boards/PKs. The necessary board/PK for each I/F is prepared depending on a system including the host for the user. Therefore, each board/PK for the different kinds of I/Fs is interconnected in order to transfer data between the different kinds of I/Fs corresponding to the plural kinds of I/Fs.
The configuration in which a plurality of same kind of I/F ports are integrated in one board/PK is described as an example of the DKC configuration in Japanese Patent Laid-open No. 2001-306265.